US38393A - Improvement in watches - Google Patents

Description

H. 8. JAMES.

Watch. 7

Patented May 5, 1863.

772m @6566 EQM her, Wining. D C.

UNITED STATES PATENT OEEicE.

HENRY B. JAMES, OF TRENTON, NEW JERSEY.

IMPROVEMENT IN WATCHES.

Specification forming part of Letters Patent No. 38,393, dated May 5, 1833; antedated November 14, 1862.

T0 aZZ whom it may concern:

Be it known that I, HENRY B. JAMES, of Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Watches and other Time-Keepers and Ido hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a plan view, on a scale larger than natural size, of the balance and balancespring of a watch and their appendages, illustrating my invention. Fig. 2 is a vertical section in the line so a: of Fig. 1.

Similar letters of reference indicate correspondin g parts in both figures.

The object of this invention is to make watches and chronometers keep time with greater exactness.

The invention consists in the employment, in a watch, chronometer, or other time-keeper, as asubstitute for the fixed stud commonly used for the support of the balance-spring, of an elastic support capable of vibrating in such a direction as to permit the spring, at each vibration of the balance, to have a movement lengthwise or in such manner that its spires have a rotary motion. I prefer to make this support of spiral or convolute form, arranged so that its spires and those of the spring will open and close alternately'at each vibration of the balance, which will allow the spring to have the movement above mentioned, at each vibration, by which means not only may the effects of expansion and contraction in length by heat and cold be counteracted and the escapement be kept in beat by keepin g the balance in a condition of equilibrium, and, if a curb is used, keeping the effective length from the curb-pins uniform, but its alternate vibration tends to make the opening and closing vibrations of the spring equal in time or isochronous, and what is more important, the impulse which the spring has lengthwise at the outer end, where it has been formerly held by the fixed stud, increases the range of motion in the balance, and consequently quickens it to make up time. By thus supporting the balance-spring, much of the variation in a watch may be prevented without any further attempt at compensation and, further, I am enabled to use a lighter mainspring, and hence to reduce very greatly the wear of the teeth of the wheels.

Fig. 1 shows the balance-spring A connected at its outer end with a flexible support, B, of convolute form. This support may be composed of one metal only, but I prefer to combine this feature of my invention with that which constitutes the subjectmatter of my Letters Patent dated December 27, 1859, by making the coil B of lamina of two metals, which expand and contract difierently with changes of temperature. The inner end of the coil B is attached to a stud, a, secured in the plate 0, but every other part is free, and the arrangement of the said coil is such that the impulses given to it by the vibration of the spring will cause it to be uncoiled slightly as the spring is coiled up, and to be coiled up slightly as the spring is uncoiled.

The two metals of which the coil 13 is composed are so arranged that the said coil will coil itself closer and uncoil itself with changes of temperature in such manner that when the temperature increases the outer end of the hair-spring may be drawn farther through the curb-pins c c, and vice versa.

' In the example represented, the most expansive metal is on the outside, and the coil B coils itself closer as the temperature increases.

To make the elastic support of the balancespring react quickly with the reaction of the balance, the outer end of the coil is extended in the form of an arm, as shown at b in Fig. 1; and in order to make a secure and at the same time as light a fastening as possible, I place the end of this arm I) and the outer end of the spring together side by side, and slip a light steel ring or clasp 0 tightly over them, enlarging the end of the arm in taper form toward the end. This enlargement of the arm b requires the clasp e to be put over the said end and into the smaller portion of the arm beyond before the spring is placed in it, and after placing the spring within it the said clasp e is drawn toward the end of the arm. The clasp 6 may be slit on one side to make it elastic, that it may make a more secure fastenin g. The stud a, by which the coil B is secured to the plate, is of slightly taper form, as shown in Fig. 2, and has a flattened head, a, below which are shoulders (6 The central turn of coil B is made into a collet and tapered inside to fit the upper part of the stud, which is pushed so tightly into it as to secure the coil to the stud firmly enough for all practical purposes. The smaller portion of the stud is inserted tightly into a taper hole in the plate (3. The coil is adjusted to increase or diminish the effective length of the balance-spring by taking hold of the head a and turning the stud in its hole in the plate in one direction or' screws 6 e,which are screwed through the rim E,

but to be generally used in combination with those screws for a more delicate and accurate adjustment; but the said screws may be used without the ordinary adjusting-screws. The said screws 6 e are secured through studs ff, which are screwed into the rim in a radial direction in the same manner as the screws (Z d. The studs f f are adjustable in the same manner as the screws 0 c, and the screws dd areadjustable in the said studs in a tangential direction, thus making a more delicate adj ustment for accurate compensation.

WVhat I claim as my invention, and desire to secure by Letters Patent, is

1. Providing an elastic vibrating support for the balance spring, substantially as herein specified. I

2. Combining the use of the elastic vibrating support for the balance spring with the system of compensation for expansion which constitutes the subject-matter of my Letters Patent of December 27, 1859, by making the said elastic support of combined lamina of two metals, substantially as herein specified.

3. The within-described mode of connecting the balance-spring and elastic vibrating support by means of the slide-ring 0, applied in combination with the enlarged end of the arm b of the said support, as herein specified.

4. Securing the elastic supporting-coil B to the plate 0 by means of the paper stud a, applied to the coil and plate in the manner herein specified.

HENRY B. JAMES.

WVitnesses PETER P. SWEET, JAMES RoeERs.

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